Rotaviruses are the most common cause of severe vomiting and diarrhea in children worldwide and infect virtually all children by 3 to 4 years of age. Each year among children younger than 5 years of age, about 440,000 deaths worldwide are attributable to rotavirus. In the United States, rotavirus only kills 20-40 children annually, but is responsible for 570,000 physician visits and 55,000 hospitalizations, costing approximately $264 million in direct health care costs and $1 billion in total costs, including the cost of time missed from work by caregivers. Rotavirus also affects adults and is more severe in the elderly
Among major worldwide causes of childhood mortality, rotavirus gastroenteritis is particularly amenable to definitive public health intervention by a suitable vaccine. A suitable vaccine would raise neutralizing antibodies, particularly in the gut, to protect against rotavirus gastroenteritis. However, production of such a vaccine has not been facile. A live, oral vaccine against rotavirus (RotaShield) was released in the United States in 1998, but was withdrawn due to a temporal association between immunization and intestinal intussusception. Therefore, a safe, effective, inexpensive, and heat-stable vaccine against rotavirus is urgently needed.